The following compounds are listed by UNEP to be POPS: • Pesticides: Aldrin, Chlordane, DDT, Dieldrin, Endrin, Heptachlor, Mirex, and Toxaphene • Industrial chemicals: Hexachlorobenzene, and PCB (polychlorinated biphenyl) • Chemical by-products (Dioxins): Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD and PCDF) This application note describes methods and results for extraction of the POPs listed above, with tables comparing ASE to traditional extraction methods.

Residue analysis in crops and food products is routinely performed in regulatory and industrial laboratories around the world. Accelerated solvent extraction is an extraction technique that speeds the extraction process and reduces the total amount of solvent used. The system uses conventional liquid solvents at elevated temperatures and pressures, which results in increased extraction kinetics. Extraction of samples ranging from 1 to 30 g typically requires 12–17 min and 15–50 mL of solvent.

Twenty chlorinated pesticides were extracted from drinking water using a Thermo Scientific Dionex AutoTrace 280 Solid Phase Extraction Instrument (AT 280). The efficiency of the Dionex AT280 method was compared to the traditional liquid-liquid phase extraction (LLE). The manual extraction required significantly more time compared to the Dionex AutoTrace 280 instrument. Analyte recovery was improved using the AT280 Automated SPE instrument for the majority of compounds without sacrificing the precision of analysis.

ASE is EPA approved under method 3545A. This technique uses high temperatures and pressures to increase the kinetics of the extraction process, thus decreasing the extraction time and solvent consumption. Also, because ASE is automated, it allows unattended extraction of up to 24 samples. In this application note, OCPs are extracted from certified reference material (CRM) BCR 115 (Institute for Reference Materials and Measurement, Geel, Belgium), an animal feed containing certified levels of organochlorine pesticides.

Accelerated Solvent Extraction (ASE) is an extraction technique that speeds the extraction process and reduces the total amount of solvent used. The system uses conventional solvents at elevated temperatures and pressures, which results in improved extraction kinetics. The Dionex ASE 300 has the capability to extract samples with volumes as large as 100 mL. This application note reports on the use of the ASE 300 for the determination of organophosphorus pesticides (OPPs) in fruits and vegetables.